AnyFont (US$1.99) enables you to add custom True Type and Open
Type fonts to your iOS device for use in any application. When I
first heard about this app, I was curious. How could an app like
this “break sandboxing,” the security feature that keeps each app
separate and safe?

Clever workaround to a frustrating limitation of iOS, but I can’t help but suspect that Apple is not going to allow this for long. If they wanted to allow the installation of additional fonts (and I dearly hope they do so in iOS 8), the feature would be built into the system.

Update: Lots of feedback from readers arguing that this is a totally legit, if obtuse to the layperson, feature of iOS 7 — and that Apple thus likely has no objection to AnyFont. Reminds of the days of Font/DA Mover.